NMR backbone assignment of the Cε4 domain of immunoglobulin E

Immunoglobulin E (IgE) plays a central role in allergic reactions. IgE is a dynamic molecule that is capable of undergoing large conformational changes. X-ray crystal structures of the Fc region of IgE in complex with various ligands have shown that IgE-Fc can exist in extended and various bent conformations. IgE-Fc consists of three domains: C epsilon 2, C epsilon 3 and C epsilon 4. While the complete NMR backbone assignments of the C epsilon 2 and C epsilon 3 domains have been reported previously, the C epsilon 4 domain has not been assigned. Here, we report the complete backbone assignment of the C epsilon 4 homodimer. C epsilon 4 can be used as a model system to study dynamics and allostery in IgE, as both molecules exist as homodimers and exhibit similar binding properties to a number of ligands.